Alert archive / Iowa / Flash Flood Warnings in 1999

Flash Flood Warning 6, NWS Des Moines, IA

May 16, 1999Butler County, Iowa

NWS Des Moines, IA issued this flash flood warning at May 16, 1999, 10:02 PM CDT for Butler County, Iowa. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
May 16, 1999, 10:02 PM CDT (03:02 UTC)
Expired
May 17, 1999, 1:00 AM CDT
In force
3 hr
Issued by
NWS Des Moines, IA
Area
Whole counties

County Butler County, IA

The radar

The Des Moines radar (KDMX), 135 km from the middle of the area, began a volume at 03:02 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 3.0 hours before the alert went out and 226 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 1999-05-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3009 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 1999-05-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 61 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
3009 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
1174 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
61 m²/s²
0-3 km storm-relative helicity
102 m²/s²
Significant tornado parameter
0.7
Supercell composite
5.9

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KDSM 170302
FFWDSM
IAC023-170600-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1002 PM CDT SUN MAY 16 1999

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  BUTLER COUNTY IN NORTH CENTRAL IOWA

* UNTIL 100 AM CDT

* AT 958 PM CDT...AREA LAW ENFORCEMENT INDICATED THAT CLUSTERS OF
  THUNDERSTORMS WITH VERY HEAVY RAIN WERE LOCATED OVER BUTLER
  COUNTY...MOVING NORTHEAST AT 30 MPH.

* EXCESSIVE RAINFALL AT THE RATE OF OVER 2 INCHES PER HOUR WILL
  PRODUCE FLOODING ACROSS BUTLER COUNTY THROUGH AT LEAST 100 AM CDT.
  SEVERAL GRAVEL ROADS WERE ALREADY WASHED OUT WITH MORE HEAVY
  RAINS ON THE WAY.

DON'T DRIVE ACROSS FLOODED ROADS! MOST FLASH FLOOD DEATHS OCCUR IN
AUTOMOBILES.

SMALL

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Des Moines, IA wrote its last area forecast discussion before this flash flood warning went out at May 16, 6:27 PM CDT, 3 hours 35 minutes earlier.

Area forecast discussion, May 16, 6:27 PM CDT, 3 hours 35 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
628PM CDT SUN MAY 16 1999

RAINFALL RATES GETTING OUT OF HAND SO ALTHOUGH ITS A LTL LATE HAVE
DECIDED TO ISSUE FLASH FLOOD WATCH FOR THE ENTIRE CWA OVNGT.  MAIN
TSTM COMPLEX TWRD MO RVR HAS YET TO REACH FA AND WITH CONVECTION
LINING UP INTO KS...SGFNT TRAINING MAY TAKE PLACE.

.DSM...FLASH FLOOD WATCH TNGT ENTIRE DMX FA.

SMALL

In the hours before

Special weather statement, May 16, 7:01 PM CDT, 3 hours 1 minute before
IAZ057-058-070-071-170015-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
701 PM CDT SUN MAY 16 1999

...TORNADO WARNING UNTIL 725 PM FOR CASS AND AUDUBON COUNTIES...

AT 7 PM RADAR INDICATED SEVERE THUNDERSTORMS EXTENDING ACROSS MOST
OF CASS COUNTY INTO EASTERN AUDUBON COUNTY. LARGE HAIL HAS BEEN
REPORTED WITH THESE STORMS. ALTHOUGH RADAR INDICATES THE ROTATION IN
THESE STORMS HAS DECREASED... THESE STORMS MAY PRODUCE A TORNADO AT
ANY TIME.

JW
Special weather statement, May 16, 7:01 PM CDT, 3 hours 1 minute before
IAZ057-058-070-071-170015-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
701 PM CDT SUN MAY 16 1999

...TORNADO WARNING UNTIL 725 PM FOR CASS AND AUDUBON COUNTIES...

AT 7 PM RADAR INDICATED SEVERE THUNDERSTORMS EXTENDING ACROSS MOST
OF CASS COUNTY INTO EASTERN AUDUBON COUNTY. LARGE HAIL HAS BEEN
REPORTED WITH THESE STORMS. ALTHOUGH RADAR INDICATES THE ROTATION IN
THESE STORMS HAS DECREASED... THESE STORMS MAY PRODUCE A TORNADO AT
ANY TIME.

JW
Special weather statement, May 16, 9:15 PM CDT, 47 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-170300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
915 PM CDT SUN MAY 16 1999

TORNADO WATCH NUMBER 272 HAS BEEN CANCELED FOR THE FOLLOWING COUNTIES
IN NORTHWEST IOWA:  POCAHANTAS...HUMBOLDT...SAC...CALHOUN...
WEBSTER...CRAWFORD...CARROLL AND GREENE.  FARTHER TO THE SOUTH AND
EAST TORNADO WATCH NUMBER 272 HAS BEEN REPLACED BY TORNADO WATCH
278 WHICH IS IN EFFECT UNTIL 300 AM.  TORNADO WATCH 278 INCLUDES THE
BIGGER CITIES OF ATLANTIC...CRESTON...AMES...DES MOINES...CLARION...
WATERLOO...CHARITON AND OTTUMWA.

FARTHER TO THE NORTH OVER THE NORTHERN TWO TIERS OF IOWA COUNTIES...
SEVERE THUNDERSTORM WATCH NUMBER 276 REMAINS IN EFFECT UNTIL 1100 PM
AND INCLUDES ALGONA...ESTHERVILLE AND MASON CITY.

PEOPLE IN AND NEAR THE WATCHES SHOULD BE PREPARED TO SEEK
SHELTER ON SHORT NOTICE.  FLASH FLOOD WATCHES ALSO REMAIN IN
EFFECT FOR THE VALID SEVERE THUNDERSTORM AND TORNADO WATCH AREAS.

SMALL
Special weather statement, May 16, 9:15 PM CDT, 47 minutes before
IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-170300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
915 PM CDT SUN MAY 16 1999

TORNADO WATCH NUMBER 272 HAS BEEN CANCELED FOR THE FOLLOWING COUNTIES
IN NORTHWEST IOWA:  POCAHANTAS...HUMBOLDT...SAC...CALHOUN...
WEBSTER...CRAWFORD...CARROLL AND GREENE.  FARTHER TO THE SOUTH AND
EAST TORNADO WATCH NUMBER 272 HAS BEEN REPLACED BY TORNADO WATCH
278 WHICH IS IN EFFECT UNTIL 300 AM.  TORNADO WATCH 278 INCLUDES THE
BIGGER CITIES OF ATLANTIC...CRESTON...AMES...DES MOINES...CLARION...
WATERLOO...CHARITON AND OTTUMWA.

FARTHER TO THE NORTH OVER THE NORTHERN TWO TIERS OF IOWA COUNTIES...
SEVERE THUNDERSTORM WATCH NUMBER 276 REMAINS IN EFFECT UNTIL 1100 PM
AND INCLUDES ALGONA...ESTHERVILLE AND MASON CITY.

PEOPLE IN AND NEAR THE WATCHES SHOULD BE PREPARED TO SEEK
SHELTER ON SHORT NOTICE.  FLASH FLOOD WATCHES ALSO REMAIN IN
EFFECT FOR THE VALID SEVERE THUNDERSTORM AND TORNADO WATCH AREAS.

SMALL

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 16, 7:35 PM CDTFlash Flood WarningDMXBlack Hawk115 min
May 16, 7:44 PM CDTTornado WarningDMXBoone, Dallas31 min
May 16, 7:52 PM CDTSevere Thunderstorm WarningDMXDallas, Madison, Polk, Warren48 min
May 16, 7:54 PM CDTFlash Flood WarningDMXBremer3 hr
May 16, 8:16 PM CDTFlash Flood WarningDMXCass3 hr
May 16, 8:17 PM CDTTornado WarningDMXBoone, Story33 min
May 16, 8:36 PM CDTSevere Thunderstorm WarningDMXJasper, Marshall49 min
May 16, 8:44 PM CDTTornado WarningDMXHamilton, Story31 min
May 16, 9:00 PM CDTTornado WarningDMXHardin50 min
May 16, 9:43 PM CDTFlash Flood WarningDMXBlack Hawk77 min
May 17, 8:47 AM CDTFlash Flood WarningDMXBlack Hawk6 hr

Nearby

Flash Flood Warnings in Iowa, 1999Every flash flood warning in 1999

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.